Marcuzzi saw a screenshot on @67for25, a Canadiens fan account he follows. It showed three racist tweets directed at P.K. Subban, Montreal’s black superstar, after the defenseman had scored the first of his two goals in Game 1. Malcolm Subban, P.K.’s younger brother, is a Bruins goaltending prospect.

Marcuzzi retweeted the screenshot. To accompany the retweet, Marcuzzi wrote that the n-word was trending in Boston. It wasn’t.

According to Social Sphere, a Cambridge company that researches and analyzes Internet data, there were eight tweets on May 1 containing the n-word and Subban’s name that could be considered racist. In response, there were 347 tweets, also featuring both words, that could be classified as condemnatory.

Social Sphere’s analysis of the tweets came a week later, and would not account for tweets that may have been deleted in the interim.

The three tweets in @67for25’s screenshot have been deleted, and Twitter has suspended the accounts. Marcuzzi, who said his intention was gallows humor instead of fact, deleted his tweet.

None of it mattered. Marcuzzi’s tweet was one accelerant on a blaze that prompted condemnation from the president of the Bruins and the mayor of Boston, stories in mainstream media (including the Globe), and another strike against a city with a checkered history in racial matters.

“I did what I could to stop the fire from spreading,” said Marcuzzi, who is also a free-lance soccer writer. “But you know how social media works. It spreads real quickly. It got out of control. It’s a shame it was taken as serious information.”

There were other intensifying factors: Bruins vs. Canadiens in the playoffs; double overtime in Game 1; the small number of black NHL players; media attention from two major markets; Francophones vs. Anglophiles; alcohol, perhaps; media emphasis on speed over accuracy; and the phenomenon of Twitter, where people can type before they think.

David Gerzof Richard, a media and marketing professor at Emerson College, looks at Twitter as a democracy of ideas. All are welcome to broadcast their opinions, even if they are vile.

“There are variables — the biggest one is removal,” said Richard. “It’s anonymity. You’re pushing buttons instead of using your vocal cords, looking someone in the eye, and saying it.

“A Twitter handle doesn’t have to be your name. If you’re @teddybear13, you may wrongly think people won’t figure out who you are. That’s another layer of anonymity. You think, ‘No one will ever know it’s me. It’s a random Twitter handle. I’m sitting alone in a room. Nobody will see me do this.’ ”

At the time of the racist tweets, the eight users had an average of 219.1 followers each. In comparison, Subban has close to 400,000.

The eight tweets could have remained in an echo chamber. This has happened before with tweets regarding successful black NHL players.

On May 5, 2013, the Islanders’ Kyle Okposo had a goal and an assist in his team’s 5-4 Game 3 overtime loss to Pittsburgh. According to Social Sphere, there was one tweet containing Okposo’s name and the n-word.

On May 10, 2013, the Capitals’ Joel Ward scored to force overtime in Game 5 against the Rangers. There were two tweets containing Ward’s name and the n-word.

On April 27, the Ducks’ Devante Smith-Pelly scored twice, including late in regulation, in Game 5 against Dallas. There were zero tweets containing Smith-Pelly’s name and the n-word.

On April 29, the Flyers’ Wayne Simmonds scored a hat trick in Game 6 against the Rangers to force Game 7. There were eight negative tweets containing Simmonds’s name and the n-word.

None of the four cases resulted in full-blown social or traditional media coverage.

With Subban, the echo chamber crumbled, likely because of two things. First, Twitter users probably ran a search using the n-word and Subban. Then, once the racist tweets were uncovered, users denounced their content.

One user retweeted one of the eight tweets, and included his response of “scumbag racist.” Another user wrote that he would block anyone who called Subban the n-word.

The condemnatory users had good intentions. But they also amplified the use of the n-word.

“Shaming on Twitter has become one of the things people do with the platform,” Richard said. “If you’ve got 20,000 followers and if some knucklehead tweets something, you really want to embarrass them and call them out. Your entire network would see that. Then they would jump on that person. It becomes this digital mob.”

The screenshot disgusted Marcuzzi. In retrospect, he said, he should have taken a deep breath and ignored it. Instead, Marcuzzi acted.

False trending alarm

To determine which topics are “trending” in a specific region, Twitter’s algorithm monitors Internet protocol addresses and cellular tower locations. From those two sources, Twitter highlights an area’s 10 most actively used words, which are then considered “trending.”

On May 1, the n-word never trended in Boston.

“I never intended it to be an informative tweet,” Marcuzzi said. “To say something is trending, I’ve used it a couple times before as an expression in humorous and not serious situations. I’ve used that kind of formula before. My followers know it. I never intended it to be information.”

But at least one of Marcuzzi’s 1,500-plus followers interpreted his tweet as fact.

Patrice Bernier, a black native of Brossard, Quebec, is captain of Major League Soccer’s Montreal Impact, and he follows Marcuzzi on Twitter. At 8:23 p.m. that night, Bernier retweeted Marcuzzi’s tweet to his 15,000 followers, along with the phrase “Too much hate!!”

This caused additional amplification. In the previous hour, there were nine tweets including the key words “Boston” and “trending.” Between 8 and 9 p.m., that number spiked to 56.

“I was kind of happy at first,” Marcuzzi said. “It showed me that people were shocked by those tweets and reacting negatively toward it. It was great for me.

“At the same time, when I realized that people were taking for granted that it was actually trending in Boston, I kind of realized it went a bit too far.”

Marcuzzi and Bernier deleted their tweets. But it was too late.

Between 10 and 11 p.m., there were 23 tweets including the words “Boston” and “trending.” Between 11 p.m. and midnight — Game 1 ended at 11:26 p.m. after Subban’s double-overtime winner — there were 203.

The Bruins communication staff monitors social and mainstream media. According to Matt Chmura, vice president of communications and content, the Bruins tracked the racist tweets on May 1 and into the next morning.

On May 2, CBS Detroit published a story saying that Bruins fans “blew up Twitter” after the Game 1 loss. The story quoted 10 racist tweets. It also quoted three tweets about the n-word trending in Boston.

Also that morning, Influence Communication, a Montreal media monitoring company, said there were 17,000 tweets containing the n-word and Subban, although most were not negative. The Canadian news site CBC posted a story citing Influence Communication’s statistic. The story also noted the n-word had trended in Boston.

Another firm, Crimson Hexagon, conducted similar research and found about 2,617 tweets containing Subban and variations of the n-word in the 24 hours beginning at game time. Of those, only about 11 percent were determined to be derogatory.

On May 2, the Bruins were scheduled to practice at noon at Wilmington’s Ristuccia Arena. That morning, several Canadian media outlets informed Chmura they would be asking the players about the racist tweets after practice.

Chmura, general manager Peter Chiarelli, and president Cam Neely discussed what to do. The media inquiries, in conjunction with the racist tweets, convinced the Bruins to act.

“We had a motive,” Chmura said. “This wasn’t a situation where we’re looking for a PR plan. We wanted to make sure that everybody knew where the organization stood on the matter so the organization wouldn’t continue to get questions about it. We wanted one singular voice to clearly establish the organization’s stance on the matter.”

At 12:15 p.m., before the dressing room opened to the media, the Bruins released the following statement, attributed to Neely:

“The racist, classless views expressed by an ignorant group of individuals following Thursday’s game via digital media are in no way a reflection of anyone associated with the Bruins organization.”

According to Globe sports editor Joe Sullivan, the racist tweets would have likely been addressed in a Bruins notebook had the team not released a statement. The notebook would have been published online May 2 and in print May 3.

That plan changed after Neely’s statement.

Traditional media outlets interviewed coach Claude Julien, Milan Lucic, Patrice Bergeron, and Brad Marchand about the racist tweets. Three of the 12 questions for Julien were about the issue.

Amalie Benjamin, the Globe’s Bruins reporter, wrote a news story on the tweets, one of three articles she wrote that day.

Boston Mayor Martin J. Walsh released a statement that afternoon.

“This is a disgrace,” Walsh said. “These racist comments are not reflective of Boston, and are not reflective of Bruins fans. I’ve said before that the best hockey in the world happens when the Bruins and Canadiens play each other, and there is no room for this kind of ignorance here.

“Yesterday [Montreal] Mayor [Denis] Coderre and I made a friendly wager on the series, and we closed the conversation by wishing each other the best. I would hope that fans on both sides would follow this example.”

The event had gone viral.

‘A digital footprint’

On May 3, the Bruins won Game 2 of the series, 5-3. After the game, Subban was interviewed about the tweets for the first time.

“It’s completely unfair for anybody to point the finger at the organization or the fan base,” Subban said. “They have passionate fans here. Great fan base.

“Since I’ve been in the league, it’s been awesome. I’ve come to Boston many times. My family has come here, and it’s been great.

“What people may say on Twitter or social media is not a reflection by any means of the league or the Boston Bruins. So whoever that is, they’ll get dealt with. But it’s completely separate from this league or the Boston Bruins organization.”

In a story published May 3, Globe sports columnist Gary Washburn wrote about the effect the incident had on Boston.

“It’s embarrassing to the city,” Washburn wrote. “It’s embarrassing to those people of color who are forced to defend Boston as a diverse and peaceful city, and embarrassing to those non-prejudiced hockey fans who disdain Subban simply because he plays for the archrival and the stakes are so high.”

The eight tweets have not been deleted. The accounts remain active. The users’ words remain etched into the granite of the Internet.

“They’re not famous in the right way,” Richard said of the users. “When they go get a job, the HR team will do some digging. If they do a Google search for their name or tweets, something tells me they’ll have some explaining to do. They’ve left a digital footprint.

“This is a little blip on Twitter. But for them, it’s something that will haunt them for a very long time.”